Investigation of Vehicle Glazing Panels

ABSTRACT

The condition of a glazing panel is investigated using a viewing device to view an illuminating electromagnetic radiation profile at a target zone. Data relating to the viewed radiation profile is compared to datum data, to produce an output related to the condition of the glazing panel at the target zone.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 11/571,173, filedJan. 7, 2008, which issued as U.S. Pat. No. 7,868,291; which is a 371national stage application claiming priority from PCT/GB2005/002510,filed Jun. 27, 2005, and GB application 0414394.7, filed Jun. 28, 2004,all of which are hereby incorporated herein by reference in theirentireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to investigation of vehicle glazing panelsparticularly to assess the condition or structural integrity of thesubject glazing panel. The invention has particular, although notexclusive, application in assessing the degree of damage to a windscreenhaving a flaw such as a break, crack or pit, and/or the quality ofrepair effected to such breaks, cracks, or pits.

2. State of the Art

Repairs are sometimes effected to vehicle glazing panels as analternative to replacement, depending upon the severity, location andnature of the crack or break. Typically, during the repair procedure,resin is introduced into the flaw crack or break and the resinsubsequently cures. The resin is selected such that, when cured, theoptical characteristics of the resin repair match as closely as possiblethe optical characteristics of the material of the glazing panel. Oftenthe resin is applied under partial vacuum or negative pressure tofacilitate de-gassing of the resin and the crack or break In certaincircumstances problems can occur in effecting a repair of adequatequality.

Certain prior art techniques have been proposed for investigatingglazing panel condition using light transmission or scattering.Exemplary prior art techniques are disclosed in, for example,DE-A-19716809 and DE-A-3640891. An improved technique has now beendevised.

SUMMARY OF THE INVENTION

The present invention seeks to provide a consistent and accurate meansof investigating the condition of a glazing panel. The term glazingpanel should be interpreted broadly to cover non glass panels inaddition to glass panels (including laminated and non-laminated glazingpanels).

According to a first aspect, the present invention provides aninvestigation method for investigating the condition of a glazing panel,the method comprising using a viewing device to view an illuminatingelectromagnetic radiation profile at a target zone of the glazing panel,wherein data relating to the viewed radiation profile is compared toother (datum) data, to produce an output related to the condition of theglazing panel at the target zone.

According to another aspect, the invention provides apparatus forinvestigating the condition of a glazing panel, the apparatuscomprising:

-   -   a viewing device to view an illuminating electromagnetic        radiation profile at a target zone of the glazing panel;    -   a processor to process data related to the viewed illuminating        radiation profile viewed by the viewing device; and,    -   an output device in communication with the processor and        arranged to produce an output related to the condition of the        glazing panel at the viewed target zone.

It is preferred that data relating to the viewed illuminating radiationprofile is compared to system stored data. Preferably, the datum orstored data is either data relating to a non flawed zone of the glazingpanel, or data bank data for a glazing panel of same type, or measureddata from a flawed zone of the screen prior to repair. Beneficially, thestored data relates to a viewed illuminating radiation profile for a nonflawed glazing panel viewed zone.

It is preferred that a readable output is given relating to thecondition of the glazing panel.

It is preferred that an illuminating radiation delivery arrangement isarranged to direct radiation into the body of the glazing panel in orderto enhance viewing of the radiation profile. Beneficially, the radiationdelivery arrangement includes a radiation delivery ring extending atleast partially about the target zone targeted by the viewing device.

The viewing device is preferably tuned to the wavelength, wavelengthband, or region of the spectrum of the illuminating radiation. In oneembodiment, radiation in the non-visible region of the spectrum isdirected into the body of the glazing panel in order to facilitateviewing. The radiation selected may be infra red radiation directed intothe body of the glazing panel in order to facilitate viewing. In certaincircumstances, the use of infra red may be preferred due to thesensitivity of certain CCD cameras to such frequencies of radiation. Inanother embodiment light in the visible range of the spectrum may beutilised. Beneficially the light is of a restricted band width orindividual wavelength. However, broadband, multiple wavelength sources(such as white light sources) may work adequately.

It is preferred that the viewing device comprises an image capturedevice. The viewing device beneficially comprises a multiplicity ofradiation sensitive pixels. Desirably the viewing device is arranged toproduce an electronic data output. In one embodiment the viewing devicebeneficially comprises an electronic camera device.

In one embodiment, the technique and apparatus utilise a dark spacechamber spacing the viewing device from the target zone. Beneficially,the dark space chamber is provided with a distal end to be placed inregister with the glazing panel, the distal end preferably including alight seal to contact the glazing panel. Advantageously, the radiationdelivery arrangement is peripherally positioned relative to the darkspace chamber.

In one embodiment the viewing device, processor and output device areprovided integrally in a hand held unit.

In an alternative embodiment, the processor may be situated remotelyfrom the viewing device and output device.

In one realisation of the technique in accordance with the invention,the flaw zone is viewed by the apparatus before and after repair and anoutput generated to quantify or gauge the quality of the repair.

In an alternative or complementary realisation of the technique of theinvention, the flaw zone is viewed after repair and an output generatedto quantify or gauge the quality of repair.

It is preferred that a backing is positioned opposed to the viewingapparatus adjacent a reverse face of the glazing panel, in order toenhance the viewing process.

In a general realisation of the invention light or other selectedradiation is transmitted through the body of the glazing panel providingbackground illumination as viewed by the viewing device. Light/radiationinteraction with a flaw (crack or break) present in the glazing panel atthe target zone causes contrast or discontinuity in the illuminationprofile viewed, when compared with the background illumination. Theviewing device provides an output signal to the processor enabling theviewed situation to be compared to a datum situation or ideal. Theoutput device enables a quality value or gauge output (such as pass orfail) to be produced.

The invention will now be described in a specific embodiment and by wayof example only, with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

The FIGURE is a schematic representation of an apparatus according tothe invention for use in performance of the method according to theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawing there is shown apparatus in accordance with theinvention comprising a hand held manually manipulatable and positionabledevice 1 for investigating the condition of a windscreen 2. The device 1comprises a housing 3 containing a CCD camera 4 positioned at a proximalend of a dark space chamber 5, defined by a peripheral chamber wall 6.The distal end of chamber 5 is either open (as shown in the drawing) ormay include a window transmissible to illuminating radiation. A filtermay be provided to inhibit certain wavelength radiation from passinginto the chamber. The CCD camera 4 targets a viewing field at the distalend of the chamber 5.

Peripherally of the chamber housing wall 6 and at the distal end of thechamber is mounted an annular array of LED's 10 arranged to outputilluminating radiation in the red light wavelength region of the visiblespectrum. The LED's direct illuminating light into the body of the glassand provide a background ‘glow’ of illuminating radiation at the targetview field of the camera 4. LED light sources are preferred due tocommercial availability of LED light sources of high quality and lowpower. The camera views the radiation profile at the glazing panel zoneat the target view field. This may be the uniform radiation ‘glow’ atundamaged/unrepaired portions within the view field, or acontrast/discontinuity profile caused by a crack or break, or repairedcrack or break. The illuminating radiation input to the camera pixelarray gives spatial and total illumination data for the target viewfield. The distal end of the chamber 5 is provided with a compressibleseal 11, to enable the device to be held against the glazing panelwithout causing damage, and to prevent ambient radiation leaking intothe chamber 5. A dark backing strip 13 may be applied to the rear of theglazing panel to provide contrast and enhance the ‘glow’ effect in thebody of the glazing panel.

The output from the camera 4 passes to a processor 7 which is able tostore and compare data output from the camera, as will be described ingreater detail hereafter. The processor outputs to an output display 8which gives a readable indication of the condition of the glazing panelto an operative using the device.

In use, the device can be held against a known undamaged portion of aglazing panel and operated to record datum situation data. As analternative datum data for a particular glazing panel may be stored, forexample in a database. The device may then be operated with a break orcrack 12 in the camera view field to record data for the damaged area ofthe glazing panel. The crack or break 12 is then repaired (typically byfilling the break or crack with resin which is subsequently cured) andthe repaired break or crack is then subjected to test. The repairedbreak or crack data can be compared with either or both of thepreviously recorded data (for the undamaged screen and the unrepairedcrack or break). The data can be processed to give a quality leveloutput (for example as a percentage of ideal result or percentageimprovement over the damaged situation) or a gauge output, such asrepair ‘pass’ or ‘fail’.

It should be readily understood that the processor could be situatedremotely from the device and communication in real time provided betweenthe local apparatus and the processor enabling the system to operate.Furthermore the data could be downloadable for post processing remotely.

1. An investigation method for investigating the condition of a glazingpanel, the method comprising: using a viewing device to view anilluminating electromagnetic radiation profile at a target zone of theglazing panel, wherein data relating to the viewed radiation profile iscompared to datum or data, to produce an output related to the conditionof the glazing panel at the target zone.
 2. An investigation methodaccording to claim 1, wherein: data relating to the viewed radiationprofile is compared to system stored data.
 3. An investigation methodaccording to claim 2, wherein: the stored data relates to a viewedradiation profile for a non flawed glazing panel viewed zone.
 4. Aninvestigation method according to claim 1, wherein: a readable output isgiven relating to the condition of the glazing panel.
 5. Aninvestigation method according to claim 1, wherein: the viewing devicecomprises an image capture device.
 6. An investigation method accordingto claim 1, wherein: the electromagnetic radiation profile viewed islight.
 7. An investigation method according to claim 1, wherein: theelectromagnetic radiation viewed is in the non-visible region of thespectrum.
 8. An investigation method according to claim 6, wherein: theelectromagnetic radiation viewed is in the infra red region of thespectrum.
 9. An investigation method according to claim 1, wherein:electromagnetic radiation is directed into the glazing panel in order tofacilitate viewing of the radiation profile.
 10. A method according toclaim 1, wherein: the target zone is viewed by the apparatus before andafter repair and an output generated to quantify or gauge the quality ofthe repair.
 11. A method according to claim 1, wherein: a backing ispositioned opposed to the viewing apparatus adjacent a reverse face ofthe glazing panel, in order to enhance the viewing process.